单项选择题

We’ve all heard how interesting Internet Shopping can be; that you can get things far cheaper than those you buy in the real shops. How convenient it is— you can shop when you want to. You can find many kinds of goods on the Internet what you’d never find on the high street. How it’s easy to compare with prices without going from one shop to another, and how there are no queues when you pay for the goods!
But before you start shopping on the Internet there are a number of questions you have to ask yourself.
Do you trust the seller
Do they have a "secure" server (安全的服务器)
What is the time when they send the goods to you
Can you contact them if the order goes wrong
Are there any hidden charges (隐藏的收费)
Most Internet Shopping sites use some sort of shopping cart (购物车)— you can place items into it. You must use a secure server, otherwise, don’t enter any information about your credit card. Don’t be afraid to email the sellers and ask them a few questions to put your mind at rest.
If there is something wrong with the server, you should ______.